MIMO Methods and Systems

ABSTRACT

A system, method, and computer program product is provided to select at least one channel based on one or more channel characteristics and initiate a first transmission to a first multiple-input-multiple-output (MIMO)-capable portable wireless device, and further initiate a second transmission to a second multiple-input-multiple-output (MIMO)-capable portable wireless device, such that at least a portion of the first transmission occurs simultaneously with at least a portion of the second transmission and both occur via a first wireless protocol; and is further configured to initiate a third transmission to a third multiple-input-multiple-output (MIMO)-capable portable wireless device via a second wireless protocol including a 802.11n protocol, where the first wireless protocol includes another 802.11 protocol other than the 802.11n protocol.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority from U.S.patent application Ser. No. 16/120,258 filed Sep. 1, 2018; which is acontinuation of U.S. patent application Ser. No. 15/824,010 filed Nov.28, 2017, now U.S. Pat. No. 10/069,548; which is a continuation of U.S.patent application Ser. No. 15/406,661 filed Jan. 13, 2017, now U.S.Pat. No. 9,859,963; which is a continuation of U.S. patent applicationSer. No. 14/952,874 filed Nov. 25, 2015, now U.S. Pat. No. 9,584,197;which is a continuation of U.S. patent application Ser. No. 14/476,628filed Sep. 3, 2014, now U.S. Pat. No. 9,503,163; which is a continuationof U.S. patent application Ser. No. 13/348,523 filed Jan. 11, 2012, nowU.S. Pat. No. 8,855,089; which is a continuation of U.S. patentapplication Ser. No. 13/118,386 filed May 28, 2011, now U.S. Pat. No.8,345,651; which is a continuation of U.S. patent application Ser. No.11/709,431 filed Feb. 21, 2007, now U.S. Pat. No. 8,009,646; whichclaims priority under 35 U.S.C. sctn.119(e) from U.S. Provisional PatentApplication Ser. No. 60/743,376 filed Feb. 28, 2006, each of theaforementioned applications is herein incorporated by reference.

FIELD OF THE INVENTION

Embodiments of the present invention relate to wireless communicationusing Multiple Input Multiple Output (“MIMO”) antennas and methods ofoperation.

BACKGROUND OF THE INVENTION

Wireless devices find uses in a variety of applications for example,providing communication between computers, wireless cells, clients,hand-held devices, mobile devices, and file servers. Wireless deviceswith Multiple Input Multiple Output (“MIMO”) antennas benefit fromspatial diversity and redundant signals. Noise sources may interferewith wireless devices that use MIMO antennas. Wireless communicationusing devices having MIMO antennas may substantially benefit fromselecting a MIMO physical sector and/or a MIMO virtual sector to improveperformance.

SUMMARY OF THE INVENTION

A system, method, and computer program product is provided to select atleast one channel based on one or more channel characteristics andinitiate a first transmission to a first multiple-input-multiple-output(MIMO)-capable portable wireless device, and further initiate a secondtransmission to a second multiple-input-multiple-output (MIMO)-capableportable wireless device, such that at least a portion of the firsttransmission occurs simultaneously with at least a portion of the secondtransmission and both occur via a first wireless protocol; and isfurther configured to initiate a third transmission to a thirdmultiple-input-multiple-output (MIMO)-capable portable wireless devicevia a second wireless protocol including a 802.11n protocol, where thefirst wireless protocol includes another 802.11 protocol other than the802.11n protocol.

BRIEF DESCRIPTION OF THE DRAWING

Embodiments of the present invention will now be further described withreference to the drawing, wherein like designations denote likeelements, and:

FIG. 1 is a diagram of an exemplary wireless device according to thevarious aspects of the present invention;

FIG. 2 is a diagram of exemplary physical sectors;

FIG. 3 is a diagram of exemplary physical sectors that form exemplaryMIMO physical sectors;

FIG. 4 is a diagram of exemplary MIMO virtual sectors;

FIG. 5 is a diagram of an exemplary MIMO virtual sector;

FIG. 6 is a diagram of exemplary MIMO virtual sectors;

FIG. 7 is a diagram of exemplary alternate method for diagrammaticallyindicating physical sectors, MIMO physical sectors, and MIMO virtualsectors;

FIG. 8 is a diagram of communication between exemplary wireless devicesin the presence of noise sources;

FIG. 9 is a diagram of an exemplary wireless device having three radiosand three antennas for each radio;

FIG. 10 is a diagram of exemplary physical sectors that form exemplaryMIMO physical sectors;

FIG. 11 is a diagram of an exemplary wireless device having two radiogroups, each group having two radios and two antennas for each radio;

FIG. 12 is a diagram of exemplary physical sectors that substantiallyoverlap to form exemplary MIMO physical sectors;

FIG. 13 is a diagram of exemplary physical sectors that partial overlapto form exemplary MIMO virtual sectors;

FIG. 14 is a diagram of exemplary physical sectors that partial overlapto form exemplary MIMO virtual sectors;

FIG. 15 is a diagram of exemplary physical sectors that partial overlapto form exemplary MIMO virtual sectors;

FIG. 16 is a diagram of exemplary physical sectors that substantiallyoverlap to form exemplary MIMO physical sectors and exemplary MIMOphysical sectors that partially overlap to form exemplary MIMO physicalsectors;

FIG. 17 is a diagram of communication between exemplary wireless devicesin the presence of noise sources;

FIG. 18 is a diagram of communication between exemplary wireless devicesin the presence of exemplary noise sources;

FIG. 19 is a diagram of a method for forming MIMO physical sectors; and

FIG. 20 is a diagram of a method for forming MIMO physical sectors.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Wireless devices use antennas to transmit and receive radio signals.Noise sources, such as other wireless devices including wireless devicesthat transmit on the same channel, may interfere with wirelesscommunication. Conventional wireless devices use a variety of techniquesto reduce the detrimental effect of noise on communication for example,dividing the area of coverage into sectors, using directional antenna,and using multiple antennas to provide redundancy and spatial diversity.

An improved wireless device, according to the various aspects of thepresent invention includes directional antennas positioned in such a waythat the physical sectors of the antennas of the wireless device overlapand the antennas selected for communication are the antennas whosephysical sectors overlap in an area in a manner that permits theantennas to operate as a Multiple Input Multiple Output (“MIMO”)antenna.

The wireless device, according to the various aspects of the presentinvention may select for communication any suitable combination ofdirectional antennas that operate as a MIMO antenna and are oriented ina desired direction of communication. Furthermore, the wireless devicemay assign any available channel to the antennas to improve performance.

A wireless device, according to the various aspects of the presentinvention includes, for example, wireless cells, access points, wirelessclients, mobile computers, and handheld devices.

The term “physical sector” is understood to mean the area of coverage inwhich an antenna transmits and receives signals. The size and shape of aphysical sector depends on a variety of factors for example, the type ofantenna, atmospheric conditions, presence of noise sources, and physicalsurroundings. Physical sectors 58, 60 and 62 represent thetwo-dimensional shape of idealized physical sectors of directionalantennas. Physical sectors 58, 60 and 62 do not overlap in FIG. 2.Physical sectors 58, 60 and 62 substantially overlap in FIG. 3. Physicalsectors 58, 60 and 62 partially overlap in FIGS. 4 and 5.

The term “MIMO antenna” is understood to mean at least two antennas thateach transmits and/or receives signals on the same channel in the areawhere the physical sectors of the antennas overlap. Antennas may bepositioned in such a way that their physical sectors overlap. Antennaswhose physical sectors overlap in the same area may be configured tooperate as a MIMO antenna in that area. Each individual antenna of aMIMO antenna operates on the same channel (e.g., frequency, encoding, orother method of dividing the radio spectrum for communication). A MIMOantenna provides, inter alia, spatial diversity between the antennas,redundancy, and temporal diversity to reduce the effects of noise ontransmission and reception. Reducing the effects of noise permits awireless device to communicate more reliability.

Antennas that form a MIMO antenna may be oriented to use differentsignal polarization for example, horizontal, vertical, and circular.Antennas that form a MIMO antenna may be physically separated to providespatial diversity.

MIMO physical sectors are formed to provide communication with increasedimmunity to noise within the area of the MIMO physical sector. The term“MIMO physical sector” means the area where the physical sectors of theantennas that operate as a MIMO antenna overlap.

In an exemplary embodiment, referring to FIG. 3, physical sectors 58,60, and 62 substantially overlap to form MIMO physical sector 82.Physical sectors 66, 68, and 70 substantially overlap to form a MIMOphysical sector 84. In this embodiment, each MIMO physical sector has anangle of coverage of about 90 degrees. In another embodiment, referringto FIG. 6, each one physical sector 58, 60, and 62 and each one physicalsector 66, 68, and 70 has an angle of coverage of about 180 degrees,thus the resulting MIMO physical sectors 82 and 84 have an angle ofcoverage of about 180 degrees. FIG. 7 represents an alternate method fordiagrammatically representing physical sectors and MIMO physicalsectors. Physical sectors 58-62 respectively have about a 180 degreeangle of coverage and the center of each physical sector is oriented atapproximately 90 degrees (straight up on the page). Each physical sector58-62 extends from wireless device 10 to the furthest extent reached bythe respective antennas even though FIG. 7 shows gaps between thephysical sectors for clarity. The MIMO physical sectors 82 and 84 ofFIGS. 6 and 7 are equivalent; however, the diagrammatical representationof FIG. 7 provides greater clarity. Thus, MIMO physical sectors 82 and84 respectively include three substantially overlapping physical sectors58-62 and 66-70.

The physical sectors of the antennas that form a MIMO antenna are notlimited to being substantially overlapping. When physical sectors onlypartially overlap, the MIMO physical sector is the area where thephysical sectors of the antennas that form the MIMO antenna overlap.Referring to FIGS. 4 and 5, the antennas associated with physicalsectors 58-62 transmit and receive using the same channel. Area 94 isthe area where physical sectors 58, 60, and 62 overlap, thus area 94 isa MIMO physical sector. The antennas associated with physical sectors58-62 operate as a MIMO antenna in area 94. The MIMO physical sectorformed by physical sectors 66-70 is also shown in FIG. 4 as MIMOphysical sector 82.

MIMO physical sectors may be formed in a variety of ways. In oneexemplary method for forming a MIMO physical sector, referring to FIG.19, antennas are selected to operate as a MIMO antenna then the antennasare positioned in such a way that the physical sectors of the antennasoverlap. In another exemplary method for forming a MIMO physical sector,referring to FIG. 20, a plurality of antennas are positioned in such away that the physical sectors of at least some of the antennas at leastpartially overlap then at least two antennas are selected to operate asa MIMO antenna in the area where their physical sectors overlap to forma MIMO physical sector. The plurality of antennas may be positioned insuch a way that the various MIMO physical sectors that are formed areoriented in different directions. At least two antennas may be selectedto operate as a MIMO antenna in accordance with the orientation of theMIMO physical sector formed by the physical sectors of the selectedantennas. The orientation of some MIMO physical sectors may provideincreased performance over the orientation of other MIMO physicalsectors. Furthermore, the antennas that form the MIMO antenna may beassigned any available channel. Accordingly, the selected antennas, thusthe MIMO physical sector, may be assigned to a channel that providesimproved performance.

The term “MIMO virtual sector” means the area where the physical sectorsof antennas that may operate as a MIMO antenna overlap. Referring toFIG. 13, physical sectors 58-62 and 66-70 each have an angle of coverageof about 180 degrees respectively. The antennas associated with physicalsectors 58-62 and 66-70 are positioned in such a way that in area 150,physical sectors 58, 68, and 70 overlap. In area 152, physical sectors58, 60, and 70 overlap and so forth for areas 154-160. Each one area150-160 comprises a MIMO virtual sector because the antennas whosephysical sectors overlap in the area may operate as a MIMO antenna. Ifthe antennas associated with physical sectors 58, 68, and 70 areselected to form a MIMO antenna, then area 150 operates as a MIMOphysical sector. If the antennas associated with physical sectors 58,60, and 70 are selected to form a MIMO antenna, then area 152 operatesas a MIMO physical sector and so forth for the other areas. Beforeantennas are selected to form a MIMO physical sector, areas 150-160 areMIMO virtual sectors. When antennas are selected to form a MIMO antenna,the area where the physical sectors of the selected antennas overlapbecome a MIMO physical sector while the other areas remain MIMO virtualsectors. A MIMO physical sector may also be referred to as a selectedMIMO virtual sector or an active MIMO virtual sector. Any criteria maybe used to select a MIMO virtual sector for communication.

The method of positioning antennas to form MIMO virtual sectors thenselecting antennas to operate as a MIMO antenna permits the wirelessdevice to respond to changes in, inter alia, performance, noise sources,and the environment by communicating through the MIMO physical sectorthat provides increased performance.

Positioning antennas to form MIMO virtual sectors permits a wirelessdevice with fixed antenna positions to select from a variety of MIMOvirtual sectors to communicate using the MIMO physical sector thatprovides a desired level of performance. When the performance of theselected MIMO physical sector deteriorates due to, inter alia, noisesources or environmental conditions, the wireless device can selectdifferent antennas to operate as a MIMO antenna, thereby selecting adifferent MIMO virtual sector to operate as a MIMO physical sector wherethe different MIMO physical sector provides increased performance.

MIMO physical sectors permits a wireless device to communicate withincreased performance. MIMO virtual sectors permits a wireless device toselect an area to transmit and receive in accordance with the MIMOvirtual sector that provides a desired level of performance. A wirelessdevice having multiple MIMO virtual sectors may select between thevarious MIMO virtual sectors. A wireless device may select the MIMOvirtual sector that provides an increased level of performance.Positioning the antennas of a wireless device to form MIMO virtualsectors that are oriented in different directions permits the wirelessdevice to select a MIMO physical sector based on the orientation of thevirtual sector with relation to the position of noise sources.

Performance may be measure by, inter alia, throughput, data throughput,signal-to-noise ratio, reduced signal error, reduced data errors,reduced retransmission requests, reduced interference, rejection ofmultipath signals, higher transmission rates, and signal strength.

A MIMO system includes radios and antennas that may be configured toform MIMO antennas, MIMO physical sectors, and MIMO virtual sectors. AMIMO system may form a MIMO antenna using any suitable combination ofradios and antennas. A MIMO system may select any suitable MIMO physicalsector for communication. A MIMO system may have any suitable number ofMIMO virtual sectors and/or selected MIMO virtual sectors. The MIMOsystem may position its MIMO physical sectors at any orientation. TheMIMO physical sectors of a MIMO system may overlap other MIMO physicalsectors of the same MIMO system. Overlapping MIMO physical sectors ofthe same MIMO system may be assigned different channels.

A MIMO system has at least two radios and at least two antennas where atleast two radios and two antennas form a MIMO antenna. In anotherexemplary embodiment, referring to FIG. 1, a MIMO system has threeradios with two antennas interfacing with each one radio. Threeantennas, one antenna from each radio, may operate as a MIMO antenna,thereby resulting in a MIMO system having two MIMO antennas.

The present invention may employ various types of radios using any typeof communication protocol and operating at any frequency and/or with anynumber of channels suitable for the application. The present inventionmay use any variety of antennas or groups of antennas for any purposefor example, transmission, reception, noise reduction, and multipathdetection. Antennas may be positioned in any manner for example, theirphysical sectors may be overlapping and non-overlapping. Radios andantennas may operate as a MIMO system, MIMO antennas, MIMO physicalsectors, and MIMO virtual sectors. Any type of algorithm and/orprocessor may be used to enable radios and/or antennas to form andoperate as MIMO antennas. Antennas may be selected for communicationaccording to any criteria such as for example, data throughput, signalstrength, signal quality, and signal-to-noise ratio.

In one embodiment, the antennas of the wireless device are positioned toform non-overlapping MIMO physical sectors and one of thenon-overlapping MIMO physical sectors is selected for communication withother wireless devices. In another embodiment, the antennas of thewireless device are positioned to form overlapping MIMO virtual sectorsand some of the MIMO virtual sectors are selected for communication withother wireless devices.

The antennas that form a MIMO antenna may be used in any manner totransmit and/or receive signals for example, any number of antennas thatoperate as the MIMO antenna may transmit only, receive only, andtransmit and receive signals.

In an exemplary embodiment, referring to FIG. 1, antennas 34, 36, and38, with their associated radios, form a MIMO antenna in which eachantenna 34, 36, and 38 transmits and receives the same signals. Inanother embodiment, antennas 34-38 form a MIMO antenna in which antenna34 transmits, antenna 36 receives only, and antenna 38 transmits andreceives. Different MIMO antenna configurations may provide differentcommunication characteristics. For example, a configuration where allantennas of the MIMO antenna transmit and receive the same informationmay provide increased error correction. A configuration where antennastransmit and/or receive different information may provide increased datathroughput. In an configuration where each antenna of the MIMO antennareceives some version of the same signal, the information content of thevarious signal versions received by the antennas of the MIMO antenna maybe highly similar and/or less similar depending on environmentalconditions for example, the presence of noise sources, multipathreflections, and spatial diversity of the antennas. Advanced algorithmsmay be used to process the signal received by each antenna that form theMIMO antenna to construct a resultant receive signal that contains asmuch of the receive signal information as can be extracted. The antennasof a MIMO antenna may be configured to receive signals from a commonsource by positioning the antennas such that their physical sectorsoverlap.

The number of antennas used to form a MIMO physical sector and theoverlap of the physical sectors of the antennas may affect performance.For example, referring to FIGS. 1 and 5, area 90 receives coverage fromonly physical sector 62, thus communications within area 90 aretransmitted and received by only antenna 38. Likewise, area 98 receivescoverage only from physical sector 60 and antenna 36. Even when antennas36 and 38 are selected to operate as a MIMO antennas, areas 90 and 98are not MIMO physical sectors because only one antenna operates in thearea. When only one antenna of the antennas selected to operate as aMIMO antenna transmits and receives in an area, the performance may notbe as high as in the areas where the physical sectors of the antennasoverlap to form a MIMO physical sector. Areas 92 and 96 receive coveragefrom physical sectors 58, 62 and 58, 60 respectively. Areas 92 and 96are MIMO physical sectors because at least two antennas operate as aMIMO antenna in the areas. Communication using at least two antennas ofthe antennas selected to operate as a MIMO antenna may improveperformance. Area 94, a MIMO physical sector formed by the overlap ofthe physical sectors of three antennas, receives coverage from physicalsectors 58, 60 and 62 and their related antennas 34-38. Antennas 34-38operate as a MIMO antenna, thus reception and/or transmission throughall three antennas in area 94 may provide higher performance thanreception and/or transmission through areas 90-92 and 96-98. The MIMOphysical sector in area 94 is most likely to provide improvedperformance because all antennas of the MIMO antenna communicate in area94.

MIMO physical sectors formed using directional antennas may useconventional antenna select methods to reduce interference from noisesources. For example, referring to FIGS. 1 and 8, wireless device 10comprises processor 12, radios 18-22, RF switches 26-30, and antennas34-38 and 42-46 where two antennas interfacing with each one RF switchrespectively. Antennas 34-38 and 42-46 operate as a first MIMO antennaand a second MIMO antenna respectively. Radios 18-22 use the802.11a/b/g/n communication protocols. Antenna physical sectors 58-62,associated with antennas 34-38 respectively, substantially overlap toform MIMO physical sector 82. Antenna physical sectors 66-70, associatedwith antennas 42-46 respectively, substantially overlap to form MIMOphysical sector 84. In this embodiment, each radio is set to the samechannel. The physical sectors and the MIMO physical sectors 82-84 extendfarther than shown in FIG. 8 to enable wireless device 10 to communicatewith wireless device 102 and receive interference from noise sources 106and 108. Wireless device 10 uses RF switches 26-30 to select betweenantennas 34-38 and 42-46. In this embodiment, the RF switches selectbetween one of two groups of antennas; either antennas 34-38 or antennas42-46 are selected, thus only one MIMO physical sector, either 82 or 84,is active at any given time. In the embodiment and the scenariodescribed in FIG. 8, wireless device 10 selects MIMO antennas physicalsector 84 to reduce interference from noise sources 106 and 108 whilecommunicating with wireless device 102. Wireless device 104 of FIG. 8may also be implemented using MIMO physical sectors similar to those ofwireless device 10. Wireless device 104 may select the MIMO physicalsector that provides the best performance while communicating withwireless device 102 and reduces interference from noise source 110.

In another embodiment of a MIMO system, referring to FIG. 9, wirelessdevice 10 comprises a processor 12, three radios 18-22, three RFswitches 26-30, and three antennas interfacing with each RF switch.Antennas 34-38, 42-46, and 50-54 may have any angle of coverage, beoriented in any direction, form MIMO antennas, and form MIMO virtualsectors in any manner. In an exemplary embodiment, referring to FIG. 10,each antenna 34-38, 42-46, and 50-54 has an angle of coverage of about120 degrees. Antennas 34-38 are oriented so that their associatedphysical sectors, 58-62 respectively, substantially overlap to form MIMOphysical sector 82. Antennas 42-46 are oriented so that their associatedphysical sectors, 66-70 respectively, substantially overlap to form MIMOphysical sector 84. Antennas 50-54 are oriented so that their associatedphysical sectors, 74-78 respectively, substantially overlap to form MIMOphysical sector 86. Physical sectors 58-62, 66-70, and 74-78 areoriented such that the center of MIMO physical sectors 82, 84, and 86are respectively oriented at about 60, 180, and 300 degreesrespectively. In this embodiment, the MIMO physical sectors do notsubstantial overlap. Each radio is set to the same channel, thus theMIMO physical sectors 82-86 each use the same channel. The wirelessdevice embodiment of FIGS. 9 and 10 may also be used to reduceinterference with noise sources by selected one of the three MIMOphysical sectors for communication.

In another embodiment, not shown, wireless device 10 comprises aprocessor, four radios, an RF switch interfacing with each one radio,and four directional antennas interfacing with each one RF switch. Eachantenna has an angle of coverage of about 90 degrees. The physicalsectors of one antenna from each RF switch substantially overlap to forma MIMO physical sector resulting in a MIMO system having four MIMOvirtual sectors. Each MIMO physical sector receives coverage from eachone of the four radios. The physical sectors of the antennas areoriented in such a way that the MIMO physical sectors do not overlap andthe MIMO physical sectors provide a combined angle of coverage of about360 degrees. All radios are set to the same channel.

In another embodiment, not shown, wireless device 10 comprises aprocessor, two radios interfacing with the processor, an RF switchinterfacing with each one of the radios, and three directional antennasinterfacing with each one RF switch. Each antenna has an angle ofcoverage of about 120 degrees. The physical sectors of one antenna fromeach one RF switch substantially overlap to form a MIMO physical sectorresulting in a MIMO system having three MIMO virtual sectors. Each MIMOphysical sector receives coverage from each one of the two radios. Thephysical sectors of the antenna are oriented in such a way that the MIMOphysical sectors do not overlap and the MIMO physical sectors provide acombined angle of coverage of about 360 degrees. All radios are set tothe same channel.

In another embodiment, not shown, wireless device 10 comprises aprocessor, two radios interfacing with the processor, an RF switchinterfacing with each one of the radios, and “N” directional antennasinterfacing with each one RF switch. Each antenna has an angle ofcoverage of about 360 degrees divided by N. Two antennas, one from eachRF switch, form a MIMO antenna, thereby forming N MIMO antennas. Thephysical sectors of the antennas that form each MIMO antennasubstantially overlap to form N MIMO physical sectors. The MIMO physicalsectors are oriented in such a way that the MIMO physical sectors do notsubstantially overlap, thereby providing a combined angle of coverage ofabout 360 degrees. All radios are set to the same channel.

Radios, antennas, and MIMO physical sectors are not limited to using asingle channel for communication or to forming MIMO physical sectorsthat are substantially non-overlapping. Radios may be grouped to provideMIMO physical sectors that use different channels. MIMO physical sectorsthat communicate on different channels may be positioned to overlap.Overlapping MIMO physical sectors that use different channels maysimultaneously communicate less mutual interference.

In one embodiment, referring to FIG. 11, wireless device 10 comprises aprocess 12, controllers 14, 16 interfaces with processor 10, two radios18, 20 interface with controller 14 thereby forming a first radio group,two radios 22, 24 interface with controller 16 thereby forming a secondradio group, an RF switch 26, 28, 30, 32 interfaces with radio 18, 20,22, 24 respectively, antennas 34-48 interface with the RF switches insuch a manner that two antennas interface with each one RF switch. Theantennas may form MIMO antennas any manner; however, forming MIMOantennas using antennas from the same group enables MIMO physicalsectors from different groups to operate on different channels.

In one embodiment, antennas 34 and 36 form a first MIMO antenna.Antennas 42 and 44 form a second MIMO antenna. The first and second MIMOantennas belong to the first radio group. Antennas 38 and 40 form athird MIMO antenna. Antennas 46 and 48 form a fourth MIMO antenna. Thethird and fourth MIMO antennas belong to the second radio group. Inanother embodiment, antennas 34-40 form a first MIMO antenna andantennas 42-48 form a second MIMO antenna.

The antennas and their respective physical sectors may have any angle ofcoverage and be oriented in any direction. The antennas of the variousgroups may form MIMO antennas in any manner. The resulting MIMO physicalsectors may be overlapping or non-overlapping. In an exemplaryembodiment, antennas 34, 36, 38, 40, 42, 44, 46, and 48 and theirrespective physical sectors 58, 60, 62, 64, 66, 68, 70, and 72 each havean angle of coverage of about 180 degrees. Referring to FIGS. 11 and 12,physical sector 58 substantially overlaps physical sector 60 to formMIMO physical sector 82. Physical sectors 62 and 64 substantiallyoverlap, 66 and 68 substantially overlap, and 70 and 72 substantiallyoverlap to form MIMO physical sectors 84, 86, and 88 respectively. Thecenter of the angles of coverage of antennas 34, 36 and 38, 40 areoriented at about 90 degrees (e.g., up the page), thus MIMO physicalsectors 82 and 84 overlap. The center of the angles of coverage ofantennas 42, 44 and 46, 48 are oriented at about 270 degrees (e.g., downthe page), thus MIMO physical sectors 86 and 88 substantially overlap.Radios 18 and 20 belong to the first radio group and radios 22 and 24belong to the second radio group. Assigning channel C1 to the firstradio group and channel C2 to the second radio group results in MIMOphysical sectors 82 and 86 using channel C1 and MIMO physical sectors 84and 88 using channel C2. Thus, the channel assignment, the antennaorientation, and the MIMO antenna configurations provide overlappingMIMO physical sectors that use different channels. Referring to FIG. 12,MIMO physical sector 82 is assigned to C1, MIMO physical sector 84 isassigned to C2, and MIMO physical sector 82 substantially overlaps MIMOphysical sector 84. Because MIMO physical sectors 82 and 84 are assigneddifferent channels, they may communicate with different wireless devicessimultaneously with less mutual interference. MIMO physical sectorsformed using antennas from different radio groups enables the MIMOphysical sectors to overlap, be assigned different channels, andcommunicate simultaneously. MIMO antennas of the same radio group usethe same channel. Interference between MIMO physical sectors formedusing antennas from the same group may be reduced by, for example,positioning the MIMO physical sectors in such a way that they do notoverlap and communicating using only one MIMO physical sector from thesame group at any one time.

In another embodiment, referring to FIG. 11, each one antenna 34-48 hasa physical sector with an angle of coverage of about 90 degrees.Antennas are organized, as described above, to form four MIMO antennas.Antenna physical sectors are positioned such that the center of theangle of coverage for antennas pairs 34 and 36, 38 and 40, 42 and 44,and 46 and 48 and their respective physical sectors are oriented at 45,135, 225, and 315 degrees respectively. Channel C1 is assigned to thefirst group radios and channel C2 is assigned to the second groupradios. The resulting four MIMO physical sectors are positioned to notsubstantially overlap and adjacent MIMO physical sectors are assigned adifferent channel. One MIMO physical sector from the first radio groupand one MIMO physical sector from the second radio group may operatesimultaneously.

The antennas of wireless device 10 may be oriented to form MIMO virtualsectors. MIMO virtual sectors may have any angle of coverage and beoriented in any manner. A MIMO virtual sector may be selected forcommunication to decrease interference. In one embodiment, referring toFIGS. 1 and 13, antennas 34-38 and 42-46 have an angle of coverage ofabout 180 degrees. Antennas 34, 36, 38, 42, 44, 46 and the center of theangle of coverage of their respective physical sectors 58, 60, 62, 66,68, 70 are oriented at 90, 150, 210, 270, 300, and 30 degreesrespectively. The area between 0 and 60 degrees, marked as area 150 inFIG. 13, is covered by physical sectors 58, 68, and 70. Antennas 34, 44,and 46 may function together as a MIMO antenna to transmit signals toand receive signals from any wireless device within area 150. Areas 152,154, 156, 158, and 160 are respectively positioned between about 60-120degrees, about 120-180 degrees, about 180-240 degrees, about 240-300degrees, and about 300-0 degrees and are serviced respectively byantennas 34, 36, and 46; 34, 36 and 38; 42, 36 and 38; 42, 44 and 38;and 42, 44 and 46. Each one area 150-160 comprises a MIMO virtualsector.

In an exemplary embodiment, referring to FIGS. 1 and 13, area 150operates as a MIMO physical sector by forming a MIMO antenna usingantennas 34, 44, and 46. Area 152 operates as a MIMO physical sector byforming a MIMO antenna using antennas 34, 36, and 46, and so forth forareas 154-160. In this embodiment, areas 158 and 160 may not be combinedto operate as a MIMO physical sector because area 158 requires antennas42, 44, and 38 to form a MIMO antenna while area 160 requires antennas42, 44, and 46 to form a MIMO antenna. Because RF switch 30 selects onlyone antenna at a time, MIMO physical sectors, for this embodiment, arelimited to any combination of any one antenna associated with each RFswitch. In this embodiment, wireless device 10 may select andcommunicate through any one MIMO virtual sector at any given time. Themethod of selecting the MIMO virtual sector consists of setting the RFswitches to select the antennas that service the desired MIMO virtualsector. In another embodiment, an RF switch with its associated antennasmay be replaced by a phased array. Antenna elements of each phased arraymay form MIMO antennas.

Antennas may be oriented in any manner to form MIMO virtual sectors ofany size. In an exemplary embodiment, referring to FIG. 13, each MIMOvirtual sector 150-160 has an angle of coverage of about 60 degrees. Inanother embodiment, referring to FIG. 14, MIMO virtual sectors 150, 152,154, 156, 158, and 160 lie between 0-30 degrees, 30-60 degrees, 60-180degrees, 180-210 degrees, 210-240 degrees, and 240-0 degreesrespectively. In another embodiment, referring to FIG. 15, each MIMOvirtual sector has an angle of coverage of about 40 degrees. MIMOvirtual sectors 150-166 lie between 0-40 degrees, 40-80 degrees, 80-120degrees, 120-160 degrees, 160-200 degrees, 200-240 degrees, 240-280degrees, 280-320 degrees, and 320-0 degrees respectively. In anotherembodiment, referring to FIGS. 11 and 18, each MIMO virtual sector hasan angle of coverage of about 90 degrees. Channel C1 is assigned to thefirst group radios and channel C2 is assigned to the second groupradios. Antenna pairs 34 and 36, 38 and 40, 42 and 44, and 46 and 48respectively form MIMO antennas. MIMO virtual sectors formed by antennas34, 36 and 42, 44 extend from 0-180 and 180-0 degrees respectively andare assigned channel C1. MIMO virtual sectors formed by antennas 38, 40and 46, 48 extend from 90-270 and 270-90 degrees respectively and areassigned channel C2. The MIMO virtual sectors are positioned to formareas 150-156 which each receive coverage from two MIMO virtual sectorsthat operate on different channels.

A wireless device may select and communicate through a MIMO virtualsector to improve performance. A wireless device may use any criteriafor selecting a MIMO virtual sector for communication such as, forexample, the presence of noise sources, noise source channels used,signal-to-strength ratio, direction of primary data flow, signalquality, signal strength, and data throughput.

In one embodiment, referring to FIGS. 9 and 17, wireless device 10desires to communicate with wireless device 102. Wireless device 10successively enables each antenna combination that forms each MIMOvirtual sector 150-160. Through each MIMO virtual sector, wirelessdevice 10 measures its ability to communicate with wireless device 102.Through at least MIMO virtual sector 150, wireless device 10 detects thepresence of noise source 110. Through at least MIMO virtual sectors 154and 156, wireless device 10 detects the presence of noise sources 106and 108 respectively. While communicating with wireless device 102,wireless device 10 may reduce interference from noise sources 106 and108 by selecting and communicating through MIMO virtual sector 150. Inthe embodiment of wireless device 10 shown in FIGS. 1 and 17, areasadjacent to the selected MIMO virtual sector have at least one antennain common, thus selecting a MIMO virtual sector does not disable allcommunication in other sectors, but communication within the selectedMIMO virtual sector may provide increased performance than adjacentareas because it transmits and/or receives using all the antennas thatform the MIMO antenna.

Referring still to FIGS. 1 and 17, wireless device 10 may reduceinterference from noise source 110 by selecting a channel that isdifferent from the channel used by noise source 110. In the event thatwireless device 102 cannot switch to a channel that is not used by noisesource 110, communication with wireless device 102 may proceed usingMIMO virtual sector 150 if it provides a desired level of performance. Awireless device may select any MIMO virtual sector that provides adesired level of performance. In this embodiment, wireless device 10 mayselect MIMO virtual sector 152 to communicate with wireless device 102.Wireless device 10 may detect less interference from noise source 110through MIMO virtual sector 152 than it detects through MIMO virtualsector 150, but wireless device 10 may also receive a less desirablesignal from wireless cell 102. In the event that wireless device 10desires to communicate with wireless device 104 and noise sources 106,108, and 110 all operate on the same channel as wireless device 104,wireless cell 10 may reduce interference from the noise sources byselecting MIMO virtual sector 160 for communicating with wireless device104. A wireless device may select and use any MIMO virtual sector forany duration of time. A wireless device may switch from using one MIMOvirtual sector to using any other MIMO virtual sector at any time andfor any purpose. In an exemplary embodiment, referring to FIG. 17,wireless device 10 switches between MIMO virtual sectors 150 and 160 tocommunicate with wireless devices 102 and 104 respectively.Additionally, a wireless device may transmit through one MIMO virtualsector and receive through a different MIMO virtual sector. In anotherembodiment, referring to FIGS. 11 and 18, wireless device 10 may selectthe MIMO virtual sector that provides a desired level of communicationfor each area. Additionally, wireless device 10 may communicate with twowireless devices 104 and 120, both in area 156, simultaneously ondifferent channels; for example, wireless device 104 communicates usingchannel C1 while wireless device 120 communicates using channel C2.

Unless contrary to physical possibility, the inventor envisions themethods and systems described herein: (i) may be performed in anysequence and/or combination; and (ii) the components of respectiveembodiments combined in any manner.

This application incorporates by reference U.S. provisional applicationSer. No. 60/484,800 filed on Jul. 3, 2003; U.S. provisional applicationSer. No. 60/493,663 filed on Aug. 8, 2003; U.S. provisional applicationSer. No. 60/692,490 filed on Jun. 21, 2005; U.S. utility applicationSer. No. 10/869,201 filed on Jun. 15, 2004 and issued under U.S. Pat.No: 7,302,278; and U.S. utility application Ser. No. 10/880,387 filed onJun. 29, 2004 and issued under U.S. Pat. No: 7,359,675, in theirentirety for the teachings taught therein.

The wireless cell can ask the advanced client to measure and reportcommunication statistics such as, but not limited to, bit error rate,signal-to-noise ratio, dropped bits, signal strength, number ofretransmission requests or any other environmental or communicationparameter. Each antenna and antenna controller functions independentlyof the other antennas and controllers.

The antenna controller sets the beam width, beam azimuth, beam steering,gain of the antenna and any other parameter available on adjustableantennas. The antennas are also capable of high-speed switching. Thecontrollable characteristics of the antenna are dynamically modifiable.The antenna beam can steer directly at one receiving client duringtransmission then pointed at a second client when transmission to thesecond client begins. The beam width of the antenna can be increased ordecreased as necessary; however, it is preferable to not increase thebeam width to provide antenna coverage beyond the width of a sector. Ifthe beam width is adjusted to provide coverage wider than a sector, theradio signal may interfere with adjacent or opposing sectors or wirelesscells or detect clients not associated with the sector or wireless cell.The processor is responsible for tracking the antenna characteristicsbest suited to service each client in the sector covered by the antennaand to set the antenna controller to the parameters best suite for theparticular client when communicating with the client. The use of anadjustable antenna, an antenna controller and a processor capable ofcontrolling the antenna controller is not limited to the six-sectorembodiment of a wireless network, but can also be used in a four-sectorwireless cell or other wireless cell types. Preferably, the beam widthwould not exceed the width of the sector of the wireless cell in whichit is used.

MIMO antennas may use any combination of spatial, polarization, or angleantenna diversity. The MIMO antenna array may be fixed or adaptive foreither transmit, receive, or both. When receiving, the MIMO antenna mayuse, for example, a maximum ratio combiner, an optimal linear combiner,selection diversity, or any combination of these methods or othermethods for combining the signals from multiple antennas into a singlesignal. When transmitting, the MIMO antenna may use any type of encodingincluding, for example, OFDM, space-time-codes, or weighting of theantenna signals in the array to accomplish beam steering.

During transmission or reception, all or any subset of antennas in theMIMO array may be used or selection diversity may be used to limit thenumber of antennas used.

Antenna diversity may be used in the transmit path, in the receive path,or in both transmit and receive paths. The signal from each antenna,transmitted or received, may or may not be weighted.

Servicing a physical sector with a MIMO antenna means that all antennasin the MIMO array use the channel assigned to the physical sector.Signal attenuation may be added after each antenna, after the signalcombiner, or in the signal processor that manipulates the incomingsignals.

Although MIMO antennas are arrays of antennas, any antenna array may beused as a single antenna or a MIMO antenna may be used. For example, adirectional antenna with about 120-degree angle of coverage may bereplaced by an antenna array that provides similar coverage. The arraymay be fixed or adaptive. Adaptive arrays may use adaptive array weightsto transmit directional beams within the angle and area of coverage tosend a stronger signal to a desired client. During reception, anadaptive array may use array weights to direct a beam substantiallytowards the transmitting client and substantially null out any sourcesof interference.

The processor, in exemplary embodiments, in addition to getting receivedata from and sending transmit data to the radios, may also sendinstructions to control the radios such as, for example, instructing aradio to change channels or getting control information from the radios.In exemplary embodiments, the processor may also be capable of, forexample, varying attenuation, controlling any or all RF switches,maintaining route tables, maintaining client specific information, andhanding off mobile clients.

In an exemplary embodiment, the processor may also control, for example,the attenuation or RF switches on a transmit or receive basis, a perclient basis, a fixed period basis, and on a per demand basis.

Some embodiments may have a network connection that may enable thewireless cell to communicate with a wired network. Some embodiments mayhave local storage to store, for example, transmit and receive date,relay data, video or audio data, environmental conditions data, and anyother type of data required to service clients, function as a network,handoff or receive mobile clients, and forward information.

When receiving, the MIMO antenna may use, for example, a maximum ratiocombiner, an optimal linear combiner, selection diversity, or anycombination of these methods or other methods for combining the signalsfrom multiple antennas into a single signal.

Assume for this example that the communication protocol uses packetizeddata and that the clients must transmit RTS and await a CTS beforetransmitting a single packet. It is possible to switch a client, ormultiple clients, from a packet-based communication protocol to a datastream protocol to increase the efficiency of long data transfersbetween clients.

Another aspect of the invention is the use of multiple directionalantennas, at least one radio, at least one attenuator and otherelectronic devices such as RF switches, packet switches, antenna sharingdevices and other electronic and electrical components to generatevarious embodiments of wireless cells and wireless networks withdiffering characteristics and capabilities.

Although there have been described preferred embodiments of this novelinvention, many variations and modifications are possible and theembodiments described herein are not limited by the specific disclosureabove, but rather should be limited only by the scope of the appendedclaims.

1. A computer-implemented method, comprising: providing access to anaccess point including: a plurality of antennas; circuitry incommunication with the plurality of antennas; and at least one radio incommunication with the circuitry; selecting at least one channel basedon one or more channel characteristics, for initiating a firsttransmission to a first multiple-input-multiple-output (MIMO)-capableportable wireless device and initiating a second transmission to asecond multiple-input-multiple-output (MIMO)-capable portable wirelessdevice, such that at least a portion of the first transmission occurssimultaneously with at least a portion of the second transmission andboth occur via a first wireless protocol; receiving first informationfrom the first multiple-input-multiple-output (MIMO)-capable portablewireless device that is based on a first measurement performed by thefirst multiple-input-multiple-output (MIMO)-capable portable wirelessdevice; receiving second information from the secondmultiple-input-multiple-output (MIMO)-capable portable wireless devicethat is based on a second measurement performed by the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device;altering at least one aspect of the first transmission in connectionwith a first multiple of the antennas, based on at least one of thefirst information or the second information, so as to direct the firsttransmission more towards the first multiple-input-multiple-output(MIMO)-capable portable wireless device as compared to the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device,thereby reducing interference between the first transmission and thesecond transmission when the at least portion of the first transmissionoccurs simultaneously with the at least portion of the secondtransmission; altering at least one aspect of the second transmission inconnection with a second multiple of the antennas, based on at least oneof the first information or the second information, so as to direct thesecond transmission more towards the secondmultiple-input-multiple-output (MIMO)-capable portable wireless deviceas compared to the first multiple-input-multiple-output (MIMO)-capableportable wireless device, thereby reducing the interference between thefirst transmission and the second transmission when the at least portionof the first transmission occurs simultaneously with the at leastportion of the second transmission; transmitting first data inconnection with the first transmission to the firstmultiple-input-multiple-output (MIMO)-capable portable wireless device,utilizing the first multiple of the antennas; transmitting second datain connection with the second transmission to the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device,utilizing the second multiple of the antennas; receiving thirdinformation from a third multiple-input-multiple-output (MIMO)-capableportable wireless device that is based on a third measurement performedby the third multiple-input-multiple-output (MIMO)-capable portablewireless device; altering at least one aspect of a third transmission inconnection with a third multiple of the antennas, based on the thirdinformation, so as to direct the third transmission towards the thirdmultiple-input-multiple-output (MIMO)-capable portable wireless device;and transmitting third data in connection with the third transmission tothe third multiple-input-multiple-output (MIMO)-capable portablewireless device, utilizing the third multiple of the antennas, via asecond wireless protocol including a 802.11n protocol, where the firstwireless protocol includes another 802.11 protocol other than the802.11n protocol.
 2. The computer-implemented method of claim 1, whereinthe third transmission to the third multiple-input-multiple-output(MIMO)-capable portable wireless device is initiated via a particularchannel that is different, in at least one respect, from the at leastone channel, for preventing interference between the third transmissionvia the 802.11n protocol, and at least one of the first transmission orthe second transmission via the another 802.11 protocol.
 3. Thecomputer-implemented method of claim 2, wherein a plurality of radiosare utilized including a first radio configured to communicate via theanother 802.11 protocol and a second radio configured to communicate viathe 802.11n protocol, and different antennas are used for the another802.11 protocol and the 802.11n protocol, so that sufficient resourcesare available to the 802.11n protocol and the another 802.11 protocol,when at least a portion of the third transmission occurs simultaneouslywith at least one of the first transmission or the second transmission.4. The computer-implemented method of claim 3, wherein the at least onechannel includes multiple channels that, together, have a greaterbandwidth than the particular channel.
 5. The computer-implementedmethod of claim 1, wherein the at least one channel includes multiplechannels including a first channel and a second channel, and the firsttransmission to the first multiple-input-multiple-output (MIMO)-capableportable wireless device is initiated via the first channel, and thesecond transmission to the second multiple-input-multiple-output(MIMO)-capable portable wireless device is initiated via the secondchannel.
 6. The computer-implemented method of claim 1, wherein thefirst transmission and the second transmission are both initiated on theat least one channel which includes the same single channel.
 7. Thecomputer-implemented method of claim 1, wherein the third transmissionto the third multiple-input-multiple-output (MIMO)-capable portablewireless device is initiated via a particular channel that is differentfrom the at least one channel.
 8. The computer-implemented method ofclaim 1, wherein the third transmission to the thirdmultiple-input-multiple-output (MIMO)-capable portable wireless deviceis initiated via a particular channel that is the same as the at leastone channel.
 9. The computer-implemented method of claim 1, wherein thefirst transmission occurs simultaneously with the second transmissionwith both the first transmission and the second transmission using allof the antennas.
 10. The computer-implemented method of claim 1, whereinthe first multiple of the antennas and the second multiple of theantennas each share at least one of the antennas.
 11. Thecomputer-implemented method of claim 1, wherein the first multiple ofthe antennas and the second multiple of the antennas are the sameantennas.
 12. The computer-implemented method of claim 1, and furthercomprising: utilizing a plurality of radios including a first radioconfigured to communicate via the another 802.11 protocol and a secondradio configured to communicate via the 802.11n protocol, so thatsufficient resources are available to the 802.11n protocol and theanother 802.11 protocol, when at least a portion of the thirdtransmission occurs simultaneously with at least one of the firsttransmission or the second transmission.
 13. The computer-implementedmethod of claim 1, wherein a channel difference is used for the 802.11nprotocol and the another 802.11 protocol for increased data throughput.14. The computer-implemented method of claim 1, wherein differentradios, different antennas, and a channel difference are used for thefirst wireless protocol and the second wireless protocol for increaseddata throughput.
 15. A computer-implemented method, comprising:positioning one or more access points so that the one or more accesspoints provide a coverage dictated by a positioner of the one or moreaccess points, each of the one or more access points including: aplurality of antennas; circuitry in communication with the plurality ofantennas; and at least one radio in communication with the circuitry;selecting at least one channel based on one or more channelcharacteristics, for initiating a first transmission to a firstmultiple-input-multiple-output (MIMO)-capable portable wireless deviceand initiating a second transmission to a secondmultiple-input-multiple-output (MIMO)-capable portable wireless device,such that at least a portion of the first transmission occurssimultaneously with at least a portion of the second transmission andboth occur via a first wireless protocol; receiving first informationfrom the first multiple-input-multiple-output (MIMO)-capable portablewireless device that is based on a first measurement performed by thefirst multiple-input-multiple-output (MIMO)-capable portable wirelessdevice; receiving second information from the secondmultiple-input-multiple-output (MIMO)-capable portable wireless devicethat is based on a second measurement performed by the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device;altering at least one aspect of the first transmission, based on atleast one of the first information or the second information, so as todirect the first transmission more towards the firstmultiple-input-multiple-output (MIMO)-capable portable wireless deviceas compared to the second multiple-input-multiple-output (MIMO)-capableportable wireless device, thereby reducing interference between thefirst transmission and the second transmission when the at least portionof the first transmission occurs simultaneously with the at leastportion of the second transmission; altering at least one aspect of thesecond transmission, based on at least one of the first information orthe second information, so as to direct the second transmission moretowards the second multiple-input-multiple-output (MIMO)-capableportable wireless device as compared to the firstmultiple-input-multiple-output (MIMO)-capable portable wireless device,thereby reducing the interference between the first transmission and thesecond transmission when the at least portion of the first transmissionoccurs simultaneously with the at least portion of the secondtransmission; transmitting first data in connection with the firsttransmission to the first multiple-input-multiple-output (MIMO)-capableportable wireless device; transmitting second data in connection withthe second transmission to the second multiple-input-multiple-output(MIMO)-capable portable wireless device; receiving third informationfrom a third multiple-input-multiple-output (MIMO)-capable portablewireless device that is based on a third measurement performed by thethird multiple-input-multiple-output (MIMO)-capable portable wirelessdevice; altering at least one aspect of a third transmission, based onthe third information, so as to direct the third transmission towardsthe third multiple-input-multiple-output (MIMO)-capable portablewireless device; and transmitting third data in connection with thethird transmission to the third multiple-input-multiple-output(MIMO)-capable portable wireless device, via a second wireless protocolincluding a 802.11n protocol, where the first wireless protocol includesanother 802.11 protocol other than the 802.11n protocol.
 16. Thecomputer-implemented method of claim 15, wherein the third transmissionto the third multiple-input-multiple-output (MIMO)-capable portablewireless device is initiated via a particular channel that is different,in at least one respect, from the at least one channel, for preventinginterference between the third transmission via the 802.11n protocol,and at least one of the first transmission or the second transmissionvia the another 802.11 protocol.
 17. The computer-implemented method ofclaim 16, wherein a plurality of radios are utilized including a firstradio configured to communicate via the another 802.11 protocol and asecond radio configured to communicate via the 802.11n protocol, anddifferent antennas are used for the another 802.11 protocol and the802.11n protocol, so that sufficient resources are available to the802.11n protocol and the another 802.11 protocol, when at least aportion of the third transmission occurs simultaneously with at leastone of the first transmission or the second transmission.
 18. Thecomputer-implemented method of claim 17, wherein the at least onechannel includes multiple channels that, together, have a greaterbandwidth than the particular channel.
 19. The computer-implementedmethod of claim 15, wherein the at least one channel includes multiplechannels including a first channel and a second channel, and the firsttransmission to the first multiple-input-multiple-output (MIMO)-capableportable wireless device is initiated via the first channel, and thesecond transmission to the second multiple-input-multiple-output(MIMO)-capable portable wireless device is initiated via the secondchannel.
 20. A computer-implemented method, comprising: providing accessto an access point including: a plurality of antennas; circuitry incommunication with the plurality of antennas; and at least one radio incommunication with the circuitry; sending a first signal to a firstmultiple-input-multiple-output (MIMO)-capable portable wireless device;receiving a second signal from the first multiple-input-multiple-output(MIMO)-capable portable wireless device; based on the second signal,permitting data communication via the access point for the firstmultiple-input-multiple-output (MIMO)-capable portable wireless device;sending a third signal to a second multiple-input-multiple-output(MIMO)-capable portable wireless device; receiving a fourth signal fromthe second multiple-input-multiple-output (MIMO)-capable portablewireless device; based on the fourth signal, permitting datacommunication via the access point for the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device;selecting at least one channel based on one or more channelcharacteristics, for initiating a first transmission to the firstmultiple-input-multiple-output (MIMO)-capable portable wireless deviceand initiating a second transmission to the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device,such that at least a portion of the first transmission occurssimultaneously with at least a portion of the second transmission andboth occur via a first wireless protocol; receiving first informationfrom the first multiple-input-multiple-output (MIMO)-capable portablewireless device that is based on a first measurement performed by thefirst multiple-input-multiple-output (MIMO)-capable portable wirelessdevice; receiving second information from the secondmultiple-input-multiple-output (MIMO)-capable portable wireless devicethat is based on a second measurement performed by the secondmultiple-input-multiple-output (MIMO)-capable portable wireless device;altering at least one aspect of the first transmission, based on atleast one of the first information or the second information, so as todirect the first transmission more towards the firstmultiple-input-multiple-output (MIMO)-capable portable wireless deviceas compared to the second multiple-input-multiple-output (MIMO)-capableportable wireless device, thereby reducing interference between thefirst transmission and the second transmission when the at least portionof the first transmission occurs simultaneously with the at leastportion of the second transmission; altering at least one aspect of thesecond transmission, based on at least one of the first information orthe second information, so as to direct the second transmission moretowards the second multiple-input-multiple-output (MIMO)-capableportable wireless device as compared to the firstmultiple-input-multiple-output (MIMO)-capable portable wireless device,thereby reducing the interference between the first transmission and thesecond transmission when the at least portion of the first transmissionoccurs simultaneously with the at least portion of the secondtransmission; transmitting first data in connection with the firsttransmission to the first multiple-input-multiple-output (MIMO)-capableportable wireless device; transmitting second data in connection withthe second transmission to the second multiple-input-multiple-output(MIMO)-capable portable wireless device; receiving third informationfrom a third multiple-input-multiple-output (MIMO)-capable portablewireless device that is based on a third measurement performed by thethird multiple-input-multiple-output (MIMO)-capable portable wirelessdevice; altering at least one aspect of a third transmission, based onthe third information, so as to direct the third transmission towardsthe third multiple-input-multiple-output (MIMO)-capable portablewireless device; and transmitting third data in connection with thethird transmission to the third multiple-input-multiple-output(MIMO)-capable portable wireless device, via a second wireless protocol.